Many processes for manufacturing a semiconductor device include treating a substrate with a chemical fluid, for example when removing a film formed on a semiconductor wafer by etching with a chemical liquid. In one example, a SiN film used as a hard mask may be removed from a wafer with hydrofluoric acid (HF) or a Si-based film may be removed with ammonia or an ammonia-hydrogen peroxide solution.
In a single-wafer film etch process, a chemical fluid is dispensed on the center of a rotating wafer and the chemical liquid flows across the wafer surface from the center of the wafer to the edge of the wafer. However, the chemical liquid cools as it flows across wafer and this is problematic since etch rate of a film on the substrate depends on the temperature of the liquid and the substrate and this can cause poor etch uniformity between the center of the substrate and the edge of the substrate. This problem becomes more pronounced as the substrate size increases.